Photosensitive resin composition and curing product thereof

ABSTRACT

A photosensitive resin composition that excels in sensitivity to actinic energy rays (photosensitivity), is hardenable within a short period of time and can form pattern through development with a diluted aqueous alkali solution and that gives a cured film through thermal curing in the postcuring step, the cured film having satisfactory flexibility and being suitable to a solder mask ink of high insulation excelling in adherence and resistances of gold plating, electroless gold plating and tin plating; and a curing product thereof. In particular, a photosensitive resin composition characterized by comprising (1) a urethane resin (A) soluble in aqueous alkali solutions, the urethane resin obtained by urethanizing in the absence of catalyst a diisocyanate compound (a), a diol compound having an ethylenically unsaturated group in its molecule (b) and a diol compound having a carboxyl group in its molecule (c) optionally together with a diol compound not having any ethylenically unsaturated group or carboxyl group in its molecule (d) and reacting the reaction product with a cyclic acid anhydride (e); (2) photopolymerization initiator (B); and (3) a reactive crosslinking agent (C).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a photosensitive resin compositionusing a polyurethane resin which is obtained by urethanization reactionwithout any catalyst followed by reaction with a cyclic acid anhydrideand is soluble in aqueous alkali solution, and a manufacturing method ofthe curing product thereof. More specifically, the present inventionrelates to a resin composition to provide a curing product havingexcellent properties including such as developing property, flexibility,adhesion property, soldering heat resistance, chemical resistance,plating resistance and high insulation, etc. is useful for such as asolder mask for flexible print wiring board; an insulation film betweenlayers for multilayer print wiring board; photosensitive light guide;and a manufacturing method of a curing product thereof; and to provide abase material and the like having a layer of the curing product.

2. Description of the Related Art

Conventionally, some part of print wiring board for personal use andmost of print wiring board for industrial use are solder masks utilizingphotolithograph. More specifically, an image is created by developingtreatment after curing with exposure, and a photocuring compositionwhich is finished with hardening with further heat and/or photoirradiation is used. A liquid composition for solder mask, which is akind of alkali development using a diluted aqueous alkali solution as adeveloping solution, is mainly used because of environmental concerns.For example, a solder mask composition, as a liquid composition forsolder mask which is an alkali development-type and uses a dilutedaqueous alkali solution, comprising a photosensitive resin which isproduced by addition of acid anhydride to the reaction product ofnovolac type epoxy resin and an unsaturated monobasic acid, aphotopolymerization initiator, a crosslinking agent, and an epoxy resinhas been disclosed. (Reference Patent 1, etc.) The curing product of thecomposition, however, is hard so that when it is applied to a Ball GridArray (BGA) base board and a flexible base board, which recently arebeing used in many fields including portable equipments, unfortunatelyit causes a crack on the surface or it cannot afford a bending property.

Another composition including such as a polybasic acid anhydridemodified epoxy acrylate resin produced by the reaction of the polybasicacid anhydride and the reaction product of polyfunctional bisphenolepoxy resin and (meth)acrylic acid, and an urethane acrylate has beendisclosed as a material applicable to a BGA base board or a flexiblebase board in Reference Patent 2. When this is used, it cannot yetafford satisfactory flexibility and it cannot follow against extremebending even though durability against cracking on the surface isimproved.

Further, another resin composition which includes a urethane resincontaining unsaturated group produced by a reaction of an unsaturatedresin containing hydroxy group, which is produced by a reaction of 0.8to 1.2 mole of an ethylenically unsaturated carboxylic acid havingaverage molecular weight between 72 and 1000 containing average onecarboxylic group and average one ethylenically unsaturated group in onemolecule to one mole of epoxy group of diepoxide; a diol compoundcontaining a carboxyl group; a diisocyanate compound; and a polyolcompound as appropriate; has been disclosed in Reference Patent 3 and 4.However, if molecular weight is increased, the acid value of the resinalso increases in a basis of resin design, and if a content of anethylenically unsaturated group is increased to increase sensitivity,the acid value of the resin decreases, and therefore, because of suchreason, it is difficult to get a well balanced molecular weight,sensitivity and developing property, and an optimization of the soldermask composition is problematic.

Photopolymeric resin composition which includes a urethane modified acidadditional vinylester resin obtained by addition of polybasic acidanhydride to an urethane modified vinylester resin composed ofvinylester resin obtained by a reaction of an epoxy compound includingmore than 1.2 epoxy group in one molecule and unsaturated monobasic acidhas been disclosed in Reference Patent 5, but it has problematicelectric property such as poor insulation property of its curingproduct, because urethane modified vinylester resin is produced by usinga catalyst when the urethane is produced.

[Reference Patent 1] Japanese Laid Open Patent S61-243869

[Reference Patent 2] Japanese Patent 2868190

[Reference Patent 3] Japanese Laid Open Patent 2001-33959

[Reference Patent 4] Japanese Laid Open Patent 2001-33960

[Reference Patent 5] Japanese Laid Open Patent H9-52925

A highly precise and highly condensed print wiring board is demanded tominimize the size of portable equipment and increase communicationspeed. Accordingly higher grade solder mask is also demanded withmaintaining more flexible property to increase electric properties suchas gold plating resistance, electroless gold plating resistance, tinplating resistance, board adhesion property and high insulationproperty. Nonetheless the present known solder mask cannot satisfy thesedemands.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the present invention is to provide a resin composition anda curing product thereof which are optimal to such as a reliable soldermask ink, which has an excellent photosensitivity to actinic energy rayswhich can draw a fine image responsible to high functions of a presentprint wiring board; wherein a pattern formation can be carried out bydevelopment with a diluted aqueous alkali solution and hardened filmobtained by thermal curing as postcuring (postcure) process hassatisfactory flexibility, high insulation, adhesion properties, goldplating resistance, electroless gold plating resistance, tin platingresistance, and prevention of peeling-off or swelling; especially asolder mask for flexible print wiring board, a insulation film betweenlayers for polylayered print wiring board and a photosensitive lightguide.

The inventors researched eagerly to carry out the above objects andcompleted the present invention.

Specifically, the present invention includes,

(1) a photosensitive resin composition comprising;

(i) urethane resin (A) soluble in aqueous alkali solution obtained by aurethanization reaction, without any catalyst, of a diisocyanatecompound (a), a diol compound (b) having an ethylenically unsaturatedgroup in its molecule; a diol compound (c) having a carboxyl group inits molecule; and a diol compound (d) not having any ethylenicallyunsaturated group or carboxyl group in its molecule as an optionalcomponent; and a reaction with a cyclic acid anhydride (e);

(ii) photopolymerization initiator (B); and

(iii) a reactive cross-linking agent (C).

Another present invention includes,

(2) the photosensitive resin composition according to (1) comprising; acuring component (D) as an optional component.

Another present invention includes;

(3) the photosensitive resin composition according to (1) or (2),wherein the solid-component acid value of the urethane resin (A) solublein aqueous alkali solution is in the range of 30 to 150 mgKOH/g.

Another present invention includes;

(4) the photosensitive resin composition according to any one of (1) to(3), wherein the diol compound (b) having the ethylenically unsaturatedgroup in its molecule is a reaction product of an epoxy compound havingtwo epoxy groups in its molecule and (meth)acrylic acid or cinnamicacid; and the cyclic acid anhydride (e) is dibasic acid monoanhydrideand/or tribasic acid monoanhydride.

Another present invention includes;

(5) the photosensitive resin composition according to any one of (1) to(4), wherein the diisocyanate compound (a) is isophorone diisocyanateand/or trimethylhexamehylene diisocyanate; the diol compound (b) havingthe ethylenically unsaturated group in its molecule is the reactionproduct of bisphenol A type epoxy resin and (meth)acrylic acid; the diol(c) having the carboxyl group in its molecule is dimethylol propionicacid; and the cyclic acid anhydride (e) is succinic anhydride.

Another present invention includes;

(6) the photosensitive resin composition according to (1) or (2),wherein the urethane resin (A) soluble in aqueous alkali solution isobtained by adding trimethylhexamethylene diisocyanate to a mixture ofdimethylol propionic acid and the reaction product of bisphenol A typeepoxy resin and methacrylic acid, and then reacting with succinicanhydride.

Another present invention includes;

(7) the photosensitive resin composition according to (5) or (6),wherein the epoxy equivalent of the bisphenol A type epoxy resin is inthe range of 100 to 900 g/equivalent.

Another present invention includes;

(8) the photosensitive resin composition according to (6), wherein anequivalent ratio, in the reaction to obtain the urethane resin (A)soluble in aqueous alkali solution, of a hydroxyl group in a mixture ofdimethylol propionic acid and the reaction product of bisphenol A typeepoxy resin and methacrylic acid, to isocyanate group oftrimethylhexamethylene diisocyanate is in the range of 1.1 to 2.0.

Another present invention includes;

(9) a manufacturing method of a curing product comprising; irradiatingactinic energy rays on the photosensitive resin composition according toany one of (1) to (8).

Another present invention includes;

(10) a base material having a layer of the curing product produced bythe manufacturing method according to (9).

Another present invention includes;

(11) a product having the base material according to (10).

Another present invention includes;

(12) a manufacturing method of a solder mask for a flexible print wiringboard, of a insulation film between layers for a multilayer print wiringboard, or of a photosensitive light guide, comprising the steps of; acoating process of a photosensitive resin composition according to anyone of (1) to (8); an irradiating process of actinic energy rays forcuring, and a treating process with alkali and/or heat.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A photosensitive resin composition of the present invention comprisesurethane resin (A) soluble in aqueous alkali solution obtained by aurethanization reaction of (i) diisocyanate compound (a); diol compound(b) having an ethylenically unsaturated group in its molecule; diolcompound (c) having a carboxyl group in its molecule; diol compound (d)not having any ethylenically unsaturated group or carboxyl group in itsmolecule as an optional component without any catalyst, and a reactionwith a cyclic acid anhydride (e); (ii) photopolymerization initiator(B); and (iii) reactive cross-linking agent (C).

Diisocyanate compound (a) used in the production of urethane resin (A)soluble in aqueous alkali solution in a photosensitive resin compositionof the present invention is not particularly limited if it has twoisocyanate groups in its molecule, and plural diisocyanates can be usedat the same time. Especially, from such a excellent flexibilitystandpoint of view, as the diisocyanate compound (a), phenylenediisocyanate, tolylene diisocyanate, xylylene diisocyanate,tetramethylxylylene diisocyanate, diphenylmethane diisocyanate,naphthalene diisocyanate, toludene diisocyanate, hexamethylenediisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate,allylenesulfonether diisocyanate, allylcyan diisocyanate, N-acyldiisocyanate, trimethylhexamethylene diisocyanate,1,3-bis-(isocyanatomethyl)cyclohexane or norbornan diisocyanate can beused, and further preferably isophorone diisocyanate ortrimethylhexamethylene diisocyanate can be used.

Diol compound (b), having an ethylenically unsaturated group, used inthe production of urethane resin (A) soluble in aqueous alkali solutionin the photosensitive resin composition of the present invention ispreferably the reaction product of an epoxy compound having two epoxygroups in its molecule and (meth)acrylic acid or cinnamic acid, and morepreferably the reaction product of bisphenol A type epoxy resin orhydrogenated bisphenol A type epoxy resin and (meth)acrylic acid. Diolcompound having an ethylenically unsaturated group in its molecule, forexample, such as the reaction product of dimethylol propionic acid and2-hydroxyethyl (meth)acrylate, the reaction product of dimethylolpropionic acid and 2-hydroxypropyl (meth)acrylate, the reaction productof dimethylol butanoic acid and 2-hydroxyethyl (meth)acrylate, thereaction product of dimethylol butanoic acid and 2-hydroxypropyl(meth)acrylate, the reaction product of an epoxy compound having twoepoxy groups in its molecule and (meth)acrylic acid or cinnamic acid,and the reaction product of a phenolic compound having two phenolichydroxyl groups in its molecule and glycidyl (meth)acrylate.

Epoxy compound having two epoxy groups in its molecule, for example, isphenyl diglycidyl ether such as hydroquinone diglycidyl ether, catecholdiglycidyl ether, resorcinol diglycidyl ether; bisphenol type epoxycompound such as bisphenol A type epoxy resin, bisphenol F type epoxyresin, bisphenol S type epoxy resin, epoxy compound of2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane; hydrogenatedbisphenol type epoxy compound such as hydrogenated bisphenol A typeepoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenatedbisphenol S type epoxy resin, epoxy compound of hydrogenated2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoroporpane; halogenatedbisphenol type epoxy compound such as brominated bisphenol A type epoxyresin, brominated bisphenol F type epoxy resin; acyclic diglycidyl ethercompound such as cyclohexanedimethanol diglycidyl ether; aliphaticdiglycidyl ether such as 1,6-hexanediol diglycidyl ether, 1,4-butanedioldiglycidyl ether, diethyleneglycol diglycidyl ether; polysulfide typediglycidyl ether compound such as polysulfide diglycidyl ether; andbiphenol type epoxy resin.

Phenol compound having two phenolic hydroxy groups in its molecule is,for example, such as hydroquinone, catechol, resorcinol,bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone,bis(4-hydroxy-3,5-dichlorophenyl)ketone, bis(4-hydroxypheny)lsulfone,bis(4-hydroxy-3,5-dimethylphenyl)sulfone,bis(4-hydroxy-3,5-dichlorophenyl)sulfone,bis(4-hydroxyphenyl)hexafluoropropane,bis(4-hydroxy-4,5-dimethylphenyl)hexafluoropropane,bis(4-hydroxy-3,5-dichlorophenyl)hexafluoropropane,bis(4-hydroxyphenyl)dimethylsilane,bis(4-hydroxy-3,5-dimethylphenyl)dimethylsilane,bis(4-hydroxy-3,5-dichlorophenyl)dimethylsilane,bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dichlorophenyl)methane,bis(4-hydroxy-3,5-dibromophenyl)methane,2,2-bis(4-hydroxyphenyl)propane,2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane,2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane,2,2-bis(4-hydroxy-3-methylphenyl)propane,2,2-bis(4-hydroxy-3-chlorophenyl)propane, bis(4-hydroxyphenyl)ether,bis(4-hydroxy-3,5-dimethylphenyl)ether,bis(4-hydroxy-3,5-dichlorophenyl)ether,9,9-bis(4-hydroxyphenyl)fluorene,9,9-bis(4-hydroxy-3-methylphenyl)fluorene,9,9-bis(4-hydroxy-3-chlorophenyl)fluorene,9,9-bis(4-hydroxy-3-bromophenyl)fluorene,9,9-bis(4-hydroxy-3-fluorophenyl)fluorene,9,9-bis(hydroxy-3-methoxyphenyl)fluorene,9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene,9,9-bis(4-hydroxy-3,5-dichlorophenyl)fluorene,9,9-bis(4-hydroxy-3,5-dibromophenyl)fluorene, 4,4′-biphenol, and3,3′-biphenol.

The reaction product of bisphenol A type epoxy resin and methacrylicacid is further preferable as diol compounds (b) having an ethylenicallyunsaturated group in its molecule used in the production of urethaneresin (A) soluble in an aqueous alkali solution in a photosensitiveresin composition of the present invention. Methacrylic acid is selectedfrom sensitivity standpoint in obtaining a curing product by actinicenergy rays irradiation and flexibility standpoint of curing product.

As a bisphenol A type epoxy resin, more preferably the epoxy resin hasthe epoxy equivalent in the range of 100 to 900 g/equivalent. If theepoxy equivalent is less than 100, a film may not be formed or itsflexibility may not be satisfactory because the molecular weight ofurethane resin (A) soluble in aqueous alkali solution produced is small,and further if the epoxy equivalent is more than 900, thephotosensitivity (light sensitivity) may decrease because anintroduction ratio of methacrylic acid decreases.

The epoxy equivalent of the present invention means the same as atraditional one, and specifically it is a mass of the epoxy compoundcontaining 1 g equivalent epoxy group. It is expressed as g/equivalentand measured by the method as directed to JIS K7236.

Bisphenol A type epoxy resin used in the production of urethane resin(A) soluble in aqueous alkali solution in the photosensitive resincomposition of the present invention includes, for example but notlimited, such as commercial Epikote 828, Epikote 1001, Epikote 1002,Epikote 103 and Epikote 1004 (manufactured by Japan Epoxy Resin Co.,Ltd.); Epomic R-140, Epomic R-301 and Epomic R-304 (manufactured byMitsui Chemical Co., Ltd.); D. E. R-331, D. E. R-332 and D. E. R-324(manufactured by Dow Chemical Co., Ltd.); Epiclon 840 and Epiclon 850(manufactured by Dainippon Ink Co., Ltd.); UVR-6410 (manufactured byUnion Carbide Corporation); and TD-8125 (manufactured by Toto Kasei Co.,Ltd.). And bisphenol A type epoxy resin having no alcoholic hydroxygroup, for example such as RE310S (manufactured by Nippon Kayaku Co.,Ltd.), is especially preferable.

A ratio of the starting materials in the reaction of bisphenol A typeepoxy resin and methacrylic acid is preferably in the range of 80 to 120equivalent % of methacrylic acid to 1 equivalent of the epoxy group ofbisphenol A type epoxy resin. If it is out of the range, gel formationmay occur while the second reaction or heat stability of urethane resin(A) soluble in aqueous alkali solution as the final product maydecrease.

A use of catalyst in the reaction is preferred to increase the reactionrate, and an amount of the catalyst is in the range of 0.1 to 10% byweight of the reaction product. A catalyst as specific example is suchas triethylamine, benzyldimethylamine, triethylammonium chloride,benzyltrimethylammonium bromide, benzyltrimethylammonium iodide,triphenylphosphine, triphenylstibine, methyltriphenylstibine, chromiumoctanoate, and zirconium octanoate, The reaction temperature is in therange of 60 to 150° C., and the reaction time is in the range ofapproximately 5 to 60 hours even though the reaction time can bedetermined case by case by monitoring the acid value, which will beexplained later.

A thermal polymerization inhibitor used is preferably hydroquinonemonomethyl ether, 2-methylhydroquinone, hydroquinone,diphenylpicrylhydrazine, diphenylamine or 2,6-di-tert-butyl-p-cresol.

The end point is the time when the acid value of the reaction solutionis not more than 1 mgKOH/g and preferably not more than 0.5 mgKOH/g.

The solid-component acid value of the present invention is an amount(mg) of potassium hydroxide required to neutralize acidity of carboxylicacid in 1 g of resin, and the acid value is an amount (mg) of potassiumhydroxide required to neutralize 1 g of the solution containing theresin, which can measured by using the standard neutralization titrationmethod as directed to JIS K0070. Also, if a concentration of the resinin the solution is known, the solid-component acid value can be obtainedby calculation from the acid value of the solution.

Diol compound (c) having a carboxyl group in its molecule used in theproduction of urethane resin (A) soluble in aqueous alkali solution inthe photosensitive resin composition of the present invention is acompound in which there are two alcoholic hydroxy groups and more thanone carboxylic group in the same molecule, and is more preferablydimethylol propionic acid and dimethylol butanoic acid(2,2-bis(hydroxymethylbutanoic acid), but not limited, which have anexcellent solubility in an aqueous alkali solution used as a developmentsolution of the composition.

Diol compound (d) as an optional component used in the production ofurethane resin (A) soluble in aqueous alkali solution in thephotosensitive resin composition of the present invention is analiphatic diol compound or alicyclic diol compound which has noethylenically unsaturated group or no carboxyl group, and in which twoalcoholic hydroxy groups are not attached to the same carbon. Such diolcompound is, for specific example, such as (poly)ethylene glycol,(poly)propylene glycol, trimethylene glycol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol,1,9-nonanediol, 1,10-decanediol, hydrobenzoin, benzpinacol,cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol,cyclohexane-1,2-dimethanol, cyclohexane-1,4-dimethanol, abutadiene-acrylonitrile copolymer having a bydroxy group at its end(e.g. ATX013 manufactured by Ube Kosan Co., Ltd.), a spiro glycol havinga hydroxyl group at its end (e.g.3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane,a dioxane glycol having a hydroxyl group at its end (e.g.2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxy-1,3-dioxane); atricyclodecane dimethanol having a hydroxyl group at its end, amacromonomer having a hydroxyl group at its end and a polystyrene sidechain (e.g. HS-6 manufactured by Toa Gousei Co., Ltd.), hydrogenatedbisphenol A, hydrogenated bisphenol F, and a reaction product of thesediol compounds and an oxide such as ethylene oxide or propylene oxide.

Cyclic acid anhydride (e) used in the production of urethane resin (A)soluble in aqueous alkali solution in the photosensitive resincomposition of the present invention is a dibasic acid monoanhydride inwhich the dibasic acid forms an intramolecular acid anhydride, atribasic acid monoanhydride in which two carboxylic groups of thetribasic acid form an intramolecular anhydride, or a mixture of suchacid monoanhydride. The dibasic acid monoanhydride, for example, is suchas maleic anhydride, succinic anhydride, itaconic anhydride, phthalicanhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,methyl endmethylene tetrahydrophthalic anhydride,methyltetrahydrophthalic anhydride; and more preferably phthalicanhydride and tetrahydrophthalic anhydride. The tribasic acid anhydride,for example, is such as trimellitic anhydride, tetrahydrotrimelliticanhydride, hexahydrotrimellitic anhydride and more preferablytrimellitic anhydride.

Especially, urethane resin (A) soluble in aqueous alkali solutionproduced by using succinic anhydride (d) has an excellent developingproperty.

Urethane resin (A) soluble in aqueous alkali solution used for thephotosensitive resin composition of the present invention can be, forexample, synthesized following procedures; premix diol compound (b)having an ethylenically unsaturated group in its molecule, diol compound(c) having a carboxyl group in its molecule, optional diol compound (d)not having any ethylenically unsaturated group or carboxyl group in apredetermined ratio in no solvent or in single or mixed solvent havingno alcoholic hydroxyl group, for example, a ketone-type solvent such asacetone, methyl ethyl ketone and cyclohexanone; an aromatic hydrocarbonsuch as benzene, toluene, xylene and tetramethylbenzene; a glycol ethersuch as ethylene glycol dimethyl ether, ethylene glycol diethyl ether,dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether,dipropylene glycol diethyl ether, trimethylene glycol dimethyl ether andtrimethylene glycol diethyl ether; an ester such as ethyl acetate, butylacetate, methyl cellosolve acetate, ethyl cellosolve acetate, butylcellosolve acetate, carbitol acetate, propylene glycol mono methyl etheracetate, dialkyl glutarate (e.g. dimethyl glutarate), dialkyl succinate(e.g. dimethyl succinate), and dialkyl adipate (e.g. dimethyl adipate);a cyclic ester such as y-butyrolactone; a petroleum solvent such aspetroleum ether, petroleum naphtha, hydrogenated naphtha and solventnaphtha; reactive crosslinking agent (C), which is explained later;heat, if needed; add gradually diisocyanate compound (a); and carry outan urethanization reaction (the first reaction) without any catalystsuch as an organometallic compound, dibutyltin dilaurate, etc.; thenreact a cyclic acid anhydride (e) to remaining alcoholic hydroxyl group(the second reaction).

An amount of diol compound (c) having a carboxyl group in its moleculeadded and reacted, as the amount of each component in the firstreaction, is a calculated amount to make 110 to 120 mgKOH/g of thesolid-component acid value at the end of reaction.

Further an amount of diisocyanate compound (a) in the first reaction ispreferably in the range of 1 to 5 of the value which is obtained bydividing the total number of mole of compound (b), compound (c) andcompound (d) with the number of mole of compound (a). If the value isless than 1, isocyanate group is remained at the end of the compoundobtained on the end of the first reaction so that it is not preferablebecause gel formation may occur. Further if the value is more than 5,the molecular weight of urethane resin (A) soluble in aqueous alkalisolution decreases so that an issue regarding a tacking property and alow sensitivity problem to actinic energy rays may easily occur.

Specifically the first reaction is an urethanization reaction in whichdimethylol propionic acid is added to the reaction solution of bisphenolA type epoxy resin and methacrylic acid and after making a suspension ora solution, trimethylhexamethylene diisocyanate and/or isophoronediisocyanate is gradually added.

The first reaction is carried out at temperature in the range of 40 to120° C. and for a period of time in the range of approximately 5 to 60hours which is properly determined from IR (Infrared) spectra, describedlater, being monitored. The above described heat polymerizationinhibitor for the reaction of bisphenol A type epoxy resin andmethacrylic acid can be used.

When the absorption at 2250 cm⁻¹ of IR spectrum assigned to isocyanategroup is disappeared, it is the end point of the reaction.

In the first reaction, an amount of trimethylhexamethylene diisocyanate(a′) is preferably set as the equivalent ratio of hydroxyl group in themixture of the reaction product (b′) of bisphenol A type epoxy resin andmethacrylic acid, and dimethylol propionic acid (c′) to isocyanate groupof trimethylhexamethylene diisocyanate (a′) is in the range of 1.1 to2.0. Specifically if the bisphenol A type epoxy resin has no alcoholichydroxyl group, an equivalent ratio can be obtained from the formula,the number of moles of compound (b′)+the number of moles of compound(c′)/the number of moles of compound (a′). When the value is not morethan 1.1, isocyanate group at the end of urethane resin (A) soluble inaqueous alkali solution is left over, it is not preferred because heatstability is poor and gel formation may occur during storage. When thevalue is more than 2, molecular weight of urethane resin (A) soluble inaqueous alkali solution becomes small so that a tacking property issuefor the curing product and a problem of lowering photosensitivity toactinic energy rays on curing.

The second reaction is the reaction in which the cyclic anhydride (e) isadded to alcoholic hydroxy group at the end of the reaction productobtained by the first reaction. The alcoholic hydroxy group is remainedat the end of the compounds produced under the above condition, towhich, for example, dibasic acid monoanhydride and/or tribasic acidmonoanhydride specifically succinic anhydride is reacted to produce asemiester so that the acid value effecting developing property can becontrolled if a curing component (D), which will be explained later, iscontained, it reacts with the semiester so that molecular weightincreases linearly and/or laddery to increase heat resistance of thecomposition.

An amount of cyclic anhydride (e) is applied less than the equivalent ofthe hydroxy group remained in the first reaction, and as thesolid-component acid value of urethane resin (A) soluble in aqueousalkali solution preferably fits in the range of 30 to 150 mgKOH/g. Ifthis solid-component acid value is not more than 30 mgKOH/g, solubilityof the photosensitive resin composition in aqueous alkali solutionextremely decreases so that, in the worst case, developing treatmentcannot be carried out and accordingly patterning cannot be carried out.In contrast, if the solid-component acid value is more than 150 mgKOH/g,solubility in aqueous alkali solution becomes so high that undesirablyadhesion property decreases and peeling-off of pattern is easilydefected.

In the second reaction, a catalyst can be used to increase reactivity ofcyclic acid anhydride (e), especially dibasic acid monoanhydride and/ortribasic acid monoanhydride and alcoholic hydroxy group. Specificexample of such catalyst is triethylamine, 4-dimethylaminopyridine,benzyldimethylamine, triethylammonium chloride, benzyltrimethylammoniumbromide, benzyltrimethylammonium iodide, triphenylphosphine,trimethylphosphine, diphenylsulfide and dimethylsulfide, etc. Reactiontemperature is preferably in the range of 60 to 130° C.

Each amount of dimethylol propionic acid and succinic acid in thereaction is calculated as solid-component acid value of urethane resin(A) soluble in aqueous alkali solution of the present invention fits inthe range of 30 to 150 mgKOH/g and is applied. If the solid-componentacid value is not more than 30 mgKOH/g, solubility in aqueous alkalisolution is not satisfactory and when pattering is carried out, it wouldbe remained as a residue and, in the worse case, patterning cannot becarried out. Further, if solid-component acid value is more than 150mgKOH/g, solubility in aqueous alkali solution becomes so high thatpattern cured by light may be undesirably peeled off.

Content of urethane resin (A) soluble in aqueous alkali solution usedfor the photosensitive resin composition of the present invention isnormally in the range of 15 to 70% by weight and preferably in the rangeof 20 to 60% by weight of solid part of the photosensitive resincomposition.

If solvent is used in the production of the urethane resin (A) solublein aqueous alkali solution, after removing the solvent using a propermethod and isolating it applies in a photosensitive resin composition,but also it can be used as a solution without removing the solvent.

Of course urethane resin (A) soluble in aqueous alkali solution used inthe present invention is soluble in aqueous alkali solution, but also itis soluble in organic solvent usable in the above production, and whenit is used as a solder resist or a plating resist, it can be developedwith the solvent.

A photosensitive resin composition of the present invention comprisesurethane resin (A) soluble in aqueous alkali solution,photopolymerization initiator (B), reactive crosslinking agent (C), andfurther comprises optional curing component (D).

All chemicals generally used for photopolymerization curing can be usedas photopolymerization initiator (B) in the photosensitive resincomposition of the present invention. Specifically, these are a benzoincompound such as benzoin, benzoin methyl ether, benzoin ethyl ether,benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutylether; an acetophenone compound such as acetophenone,2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone,2-hydroxy-2-methylphenylpropan-1-one, diethoxyacetophenone,1-hydroxycyclohexyl phenyl ketone, and2-methyl-1-(4-(methylthio)phenyl)-2-morphorinopropan-1-one; ananthraquinone compound such as 2-ethylanthraquinone,2-tert-butylanthraquinone, 2-chloroanthraquinone, and2-amylanthraquinone; a thioxanthone compound such as2-4,-diethylthioxanthone, 2-isoprpylthioxanthone, and2-chlorothioxanthone; a ketal compound such as acetophenone dimethylketal, and benzyl dimethyl ketal; a benzophenone compound such asbenzophenone, 4-benzoyl-4′-methyl-diphenylsufide and4,4′-bismethylaminobenzophenone; a phosphine oxide compound such as2,4,6-trimethylbenzoyldiphenylphosphine oxide, andbis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. A content ratio ofphotopolymerization initiator (B) is generally in the range of 1 to 30%by weight and preferably in the range of 2 to 25% by weight of solidpart, as 100% by weight, of the photosensitive resin composition. Thesecompounds can be used as single compound or a mixture of more than twokinds of compound, and further can be used with a reaction promotingagent, a tertiary amine such as triethanolamine andmethyldiethanolamine; or a benzoic acid derivative such asN,N-dimethylaminobenzoic acid ethyl ester and N,N-dimethylaminobenzoicacid isoamyl ester. A proper amount of the reaction promoting agent isless than 100% by weight of photopolymerization initiator (B), and itcan be used if need.

Reactive Cross-linking agent (C) used for a photosensitive resincomposition of the present invention is a (meth)acrylate derivative,i.e. such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, 1,4-butanediol mono(meth)acrylate, carbitol(meth)acrylate, acryloyl morpholine, a semiester which is a reactionproduct of (meth)acrylate having hydroxy group and polycarboxylic acidanhydride, polyethylene glycol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, trimethylol propane polyethoxytri(meth)acrylate,glycerine polypropoxytri(meth)acrylate, di(meth)acrylate which is areaction product of hydroxypivalic acid neopentylglycol andε-caprolactone (e.g. Kayarad HX-220 and HX-620, manufactured by NipponKayaku Co., Ltd.), pentaerythrytol tetra(meth)acrylate,poly(meth)acrylate which is a reaction product of dipentaerytlirytol andε-caprolatone, and epoxy (meth)acrylate which is a reaction product ofmono or poly glycidyl acrylate and (meth)acrylic acid.

(Meth)acrylate having hydroxy group in a semiester, which is a reactionproduct of polycarboxylic acid anhydride, as the reactive crosslinkingagent (C) is, for example, such as 2-hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, and 1,4-butandiol mono(meth)acrylate.

Polycarboxylic acid anhydride is, for example, such as succinicanhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalicanhydride and hexahydrophthalic anhydride.

Mono or poly glycidyl compound in epoxy (meth)acrylate, which is areaction product of mono or poly glycidyl compound and (meth)acrylicacid, as the reactive crosslinking agent (C) is, for example, such asbutyl glycidyl ether, phenyl glycidyl ether, polyethylene glycoldiglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanedioldiglycidyl ether, hexahydrophthalic acid diglycidyl ester, glycerinpolyglycidyl ether, glycerin polyethoxyglycidyl ether,trimethylolpropane polyglycidyl ether and trimethylol propanepolyethoxypolyglycidyl ether.

Content of a reactive crosslinking agent (C) is in the range of 2 to 40%by weight and preferably in the range of 3 to 30% by weight wherein thesolid part of the photosensitive resin composition is 100%.

Curing component (D) used for the photosensitive resin composition ofthe present invention as an optional component is such as an epoxycompound and an oxazine compound. Curing component (D) reacts withcarboxyl group remained in the coated resin film after light curing byheating and it is especially preferred when farther strong chemicalresistant coated resin film is needed.

Specific example of the epoxy compound as curing component (D) includessuch as phenol novolac type epoxy resin, cresol novolac type epoxyresin, trishydroxyphenylmethane type epoxy resin, dicyclopentadienephenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F typeepoxy resin, biphenol type epoxy resin, bisphenol A novolac type epoxyresin, an epoxy resin having naphthalene skeleton and heterocyclic epoxyresin.

Phenol novolac type epoxy resin is, for example, Epicron N-770(Dainippon Ink Chemical Industries Co., Ltd.), D. E. N438 (manufacturedby Dow Chemical Co., Ltd.), Epicoat 154 (manufactured by Japan EpoxyResin Co., Ltd.), and RE-306 (manufactured by Nippon Kayaku Co., Ltd.).

Cresol novolac type epoxy resin is, for example, Epicron-695(manufactured by Dainippon Ink Chemical Industries Co., Ltd.),EOCN-102S, EOCN-103S and EOCN-104S (manufactured by Nippon Kayaku Co.,Ltd.), UVR-6650 (manufactured by Union Carbide Co., Ltd.), and ESCN-195(manufactured by Sumitomo Chemical Industries Co., Ltd.).

Trishydroxyphenylmethane type epoxy resin is, for example, EPPN-503,EPPN-502H and EPPN-501H (manufactured by Nippon Kayaku Co., Ltd.),TACTIX-742 (manufactured by Dow Chemical Co., Ltd.), and EpicoatE1032H60 (manufactured by Japan Epoxy Resin Co., Ltd.).

Dicyclopentadiene phenol type epoxy resin is, for example, EpicronEXA-7200 (manufactured by Dainippon Ink Chemical Industries Co., Ltd.),and TACTIX-556 (manufactured by Dow Chemical Co., Ltd.).

Bisphenol type epoxy resin is, for example, bisphenol A type epoxy resinsuch as Epicoat 828 and Epicoat 1001 (manufactured by Japan Epoxy ResinCo., Ltd.), UVR-6410 (manufactured by Union Carbide Co., Ltd.), D. E.R-331 (manufactured by Dow Chemical Co., Ltd.) and YD-8125 (manufacturedby Toto Kasei Co., Ltd.); and bisphenol F type epoxy resin such asUVR-6490 (manufactured by Union Carbide Co., Ltd.) and YDF-8170(manufactured by Toto Kasei Co., Ltd.).

Biphenol type epoxy resin is, for example, biphenol type epoxy resinsuch as NC-3000 and NC-3000H (manufactured by Nippon Kayaku Co., Ltd.);bixylenol type epoxy resin such as YL-6121 (manufactured by Japan EpoxyResin Co., Ltd.); and the like.

Bisphenol A novolac type epoxy resin is, for example, Epicron N-880(manufactured by Dainippon Ink Chemical Industries Co., Ltd.) andEpicoat E157S75 (manufactured by Japan Epoxy Resin Co., Ltd.), andYX-8000 (manufactured by Japan Epoxy Resin Co., Ltd.) also can beemployed.

Epoxy resin having naphthalene skeleton is, for example, such as NC-7000and NC-7300 (manufactured by Nippon Kayaku Co., Ltd.); and EXA-4750(manufactured by Dainippon Ink Chemical Industries Co., Ltd.).

Cyclic epoxy resin is, for example, such as EHPE-3150 (manufactured byDaicel Chemical Industries Co., Ltd.). Heterocyclic epoxy resin is, forexample, such as TEPIC-L, TEPIC-H and TEPIC-S (manufactured by NissanChemical Industries Co., Ltd.).

Oxazin compound as curing component (D) is, for example, such as B-mtype benzoxazine, P-a type benzoxazine and B-a type benzoxazine(manufactured by Shikoku Chemical Industries Co., Ltd.).

Curing component (D) is preferably NC-3000 or YX-4000 which is biphenoltype epoxy resin; and TEPIC-L, TEPIC-H or TEPIC-S which is heterocyclicepoxy resin.

Content ratio of curing component (D) is preferably not more than 200%equivalent calculated from the solid-component acid value and quantityconsumed of urethane resin (A) soluble in aqueous alkali solution of thepresent invention. If the amount is more than 200%, developing propertyof the photosensitive resin composition of the present invention notpreferably decreases extremely.

Further, according to need, such as various fillers and additives; forexample, a filler such as talc, barium sulfate, calcium carbonate,magnesium carbonate, barium titanate, aluminum hydroxide, aluminumoxide, silica and clay; thixotropic agent such as aerosil; coloringagent such as phthalocyanine blue, phthalocyanine green and titaniumoxide; and leveling agent and antifoaming agent such as silicone andfluoride type compound; polymerization inhibitor such as hydroquinoneand hydroquinone monometbyl ether can be added to increase variousproperties of the composition.

Further, such as melamine can be added as a thermal curing catalyst.

Specifically when above curing component (D) is used, it can be premixedinto the resin composition or mixed prior to coating to a print wiringboard. Specifically two kinds of solution which are the main solutionincluding mainly (A) component and a promoter for epoxy curing, andcuring solution including mainly curing component (D) can be mixed priorto use. In this case, B and C components can be added adequately to themain solution or to the curing solution for use. A solvent used to makethe solution can be the same solvent as used to synthesize urethaneresin (A) soluble in aqueous alkali solution or another solventdisclosed as an example for urethanization reaction solvent can be usedin separate or in mixing.

The photosensitive resin composition of the present invention can beused as a dry-film type solder mask having a sandwich structure in whichthe resin composition is sandwiched between a support film and aprotection film.

The photosensitive resin composition (liquid or film) of the presentinvention not only is useful for an insulation material of electronicpart; a solder mask for a light guide and a print base board which isconnecting between light parts; and a resist material for such as acover ray; but also can be used as a color filter, a printing ink, asealant, a coating agent, and an adhesive.

The present invention includes a method of curing product which cures byirradiation of actinic energy rays such as ultraviolet light to thephotosensitive resin composition. The curing by irradiation of actinicenergy rays such as ultraviolet light can be carried out as usual. Forexample, when ultraviolet light is irradiated, an ultraviolet lightmeans such as a low-pressure mercury lamp, a high-pressure mercury lamp,an ultrahigh-pressure mercury lamp, a xenon lamp, and an ultravioletemission laser (such as an excimer laser) can be used.

The curing product of the photosensitive resin composition of thepresent invention can be used for a base material, for example, such asa resist film; a print base board as an insulation film between layersfor a build-up method or a light guide; and an electric part, anelectronic part and a light part such as a light electronic board or alight board. Specific example having these base materials is, forexample, a home electronic product such as a computer and a liquiddisplay, and portable equipment such as a cellular telephone.

A thickness of this curing product layer is approximately in the rangeof 0.5 to 160 μm and preferably in the range of 1 to 100 μm.

The present invention includes manufacturing methods of the solder maskfor flexible print wiring board, the insulation film between layers formultilayer print wiring board or the photosensitive light guide, whichcomprise steps of, coating of the photosensitive resin composition ofthe present invention; curing by irradiation of actinic energy rays; andprocessing with alkali treatment and/or thermal treatment. For example,we explain specifically about the flexible print wiring board. When aliquid resin composition is used, the photosensitive resin compositionof the present invention is coated with the film thickness in the rangeof 0.5 to 160 μm using such as a screen printing method, a spray method,a roll coat method, a static electric coating method, a curtain coatmethod, and is dried at normally in the range of 50 to 110° C. andpreferably in the range of 60 to 100° C.

Then, an actinic energy ray such as ultraviolet light is irradiateddirectly or indirectly to the coating film through the photomask formingan exposure pattern of such as negative film, of which the strength isapproximately in the normal range of 10 to 200 mJ/cm², and thenunexposed part is developed by such as spraying, immersing with shaking,brushing, and scrapping using a developing solution, which is explainedlater. If it is necessary, an actinic energy ray such as ultravioletlight is irradiated and then it is treated normally at temperature inthe range of 100 to 200° C. and preferably in the range of 140 to 180°C. to give a print wiring board having a permanent protective film withan excellent gold plating property and satisfactory anti-warpingproperty, high insulation property, heat resistance, chemicalresistance, acid resistance, adhesion property, and bending property.

Aqueous alkali solution used for development is an inorganic aqueoussolution of such as potassium hydroxide, sodium hydroxide, sodiumcarbonate, potassium carbonate, sodium bicarbonate, potassiumbicarbonate, sodium phosphate and potassium phosphate; and an organicaqueous alkali solution of such as tetramethylammonium hydroxide,tetraethylammonium hydroxide, tetrabutylammonium hydroxide,monoethanolamine, and diethanolamine.

EXAMPLES

According to the examples, we explain specifically the presentinvention, but not limited to the present examples.

Synthetic Example 1

508.52 g (1.000 mole) of Kayarad R-115 (manufactured by Nippon KayakuCo., Ltd., bisphenol A type epoxy acrylate, Molecular weight 508.52),diol compound (b) having the ethylenically unsaturated group in itsmolecule; 134.93 g (1.006 mole) of dimethylol propionic acid, diolcompound (c) having the carboxyl group in its molecule; 297.26 g (1.337mole) of isophorone diisocyanate, diisocyanate compound (a); 561.04 g ofdiethylene glycol monoethyl ether acetate, solvent; and 4.81 g of2,6-di-tert-butyl-p-cresol, thermal polymerization inhibitor; were mixedin a 2 L flask with 4 necks; and the mixture was reacted for 3 hours at60° C. and for 4 hours at 80° C. until absorbance at about 2250 cm⁻¹ ofIR (Infrared) spectrum disappeared. After reaction, the solid-componentacid value was 60 mgKOH/g. To this reaction solution, 101.22 g (0.665mole) of tetrahydrophthalic anhydride as a cyclic acid anhydride (e) and0.16 g of 4-dimethylaminopyridine as a catalyst were added and themixture was reacted for 4 hours at 95° C. to give the resin solutioncontaining 65% by weight of urethane resin (A) soluble in aqueous alkalisolution. This resin solution is referred as A-1. The acid valuemeasured was 59 mgKOH/g (the solid-component acid value; 91 mgKOH/g).

Synthetic Example 2

540.18 g (1.000 mole) of Kayarad R-9467 (manufactured by Nippon KayakuCo., Ltd., bisphenol A type epoxy acrylate, Molecular weight 540.18),diol compound (b) having the ethylenically unsaturated group in itsmolecule; 139.20 g (1.038 mole) of dimethylol propionic acid, diolcompound (c) having the carboxyl group in its molecule; 100.66 g (0.453mole) of isophorone diisocyanate and 190.43 g (0.906 mole) oftrimethylhexamethylene diisocyante, diisocyanate compound (a); 578.76 gof diethylene glycol monoethyl ether acetate, solvent; and 4.81 g of2,6-di-tert-butyl-p-cresol, thermal polymerization inhibitor; were mixedin a 2 L flask with 4 necks; and the mixture was reacted for 3 hours at60° C. and for 4 hours at 80° C. until absorbance at about 2250 cm⁻¹ ofIR spectrum disappeared. After reaction, the solid-component acid valuewas 60 mgKOH/g. To this reaction solution, 104.37 g (0.686 mole) oftetrahydrophthalic anhydride as a cyclic acid anhydride (e) and 0.16 gof 4-diemthylaminopyridine as a catalyst were added and the mixture wasreacted for 4 hours at 95° C. to give the resin solution containing 65%by weight of urethane resin (A) soluble in aqueous alkali solution. Thisresin solution is referred as A-2. The acid measured value was 58mgKOH/g (the solid-component acid value: 89 mgKOH/g).

Synthetic Example 3

508.52 g (1.000 mole) of Kayarad R-115 (manufactured by Nippon KayakuCo., Ltd., bisphenol A type epoxy acrylate, Molecular weight 508.52),diol compound (b) having the ethylenically unsaturated group in itsmolecule; 104.88 g (0.782 mole) of dimethylol propionic acid, diolcompound (c) having the carboxyl group in its molecule; 264.06 g (1.188mole) of isophorone diisocyanate, diisocyanate compound (a); 510.76 g ofdiethylene glycol monoethyl ether acetate, solvent; and 4.81 g of2,6-di-tert-butyl-p-cresol, thermal polymerization inhibitor; were mixedin a 2 L flask with 4 necks; and the mixture was reacted for 3 hours at60° C. and for 4 hours at 80° C. until absorbance at about 2250 cm⁻¹ ofIR spectrum disappeared. After reaction, the solid-component acid valuewas 50 mgKOH/g. To this reaction solution, 71.09 g (0.370 mole) oftrimellitic anhydride as a cyclic acid anhydride (e) and 0.16 g of4-dimethylaminopyridine as a catalyst were added and the mixture wasreacted for 4 hours at 95° C. to give the resin solution containing 65%by weight of urethane resin (A) soluble in aqueous alkali solution. Thisresin solution is referred as A-3. The acid value measured was 60mgKOH/g (the solid-component acid value: 92 mgKOH/g).

Synthetic Example 4

540.18 g (1.000 mole) of Kayarad R-9467 (manufactured by Nippon KayakuCo., Ltd., bisphenol A type epoxy acrylate, Molecular weight 540.18),diol compound (b) having the ethylenically unsaturated group in itsmolecule; 261.38 g (1.949 mole) of dimethylol propionic acid, diolcompound (c) having the carboxyl group in its molecule; 413.35 g (1.966mole) trimethylhexamethylene diisocyanate, diisocyanate compound (a);678.49 g of diethylene glycol monoethyl ether acetate, solvent; and 5.0g of 2,6-di-tert-butyl-p-cresol, thermal polymerization inhibitor; weremixed in a 2 L flask with 4 necks; and the mixture was reacted for 3hours at 60° C. and for 4 hours at 80° C. until absorbance at about 2250cm⁻¹ of IR spectrum disappeared. After reaction, the solid-componentacid value was 90 mgKOH/g. To this reaction solution, 45.14 g (0.297mole) of tetrahydrophthalic anhydride as a cyclic acid anhydride (e),and 0.15 g of 4-diemthylaminopyridine as a catalyst were added and themixture was reacted for 4 hours at 95° C. to give the resin solutioncontaining 65% by weight of urethane resin (A) soluble in aqueous alkalisolution. This resin solution is referred as A-4. The acid valuemeasured was 66 mgKOH/g (the solid-component acid value: 102 mgKOH/g).

Synthetic Example 5

512.12 g (1.000 mole) of Kayarad R-9451 (manufactured by Nippon KayakuCo., Ltd., bisphenol A type epoxy acrylate, Molecular weight 512.12),diol compound (b) having the ethylenically unsaturated group in itsmolecule; 508.01 g (3.429 mole) of dimethylol butanoic acid, diolcompound (c) having the carboxyl group in its molecule; 101.26 g (0.857mole) of 1,6-hexanediol, diol compound (d) not having any ethylenicallyunsaturated group or carboxylic group in its molecule; 903.77 g (4.066mole) of isophorone diisocyanate, diisocyanate compound (a); 1350.11 gof diethylene glycol monoethyl ether acetate, solvent; and 6.87 g of2,6-di-tert-butyl-p-cresol, thermal polymerization inhibitor; were mixedin a 4 L flask with 4 necks; and the mixture was reacted for 3 hours at60° C. and for 4 hours at 80° C. until absorbance at about 2250 cm⁻¹ ofIR spectrum disappeared. After reaction, the solid-component acid valuewas 95 mgKOH/g. To this reaction solution, 37.63 g (0.247 mole) oftetrahydrophthalic anhydride as a cyclic acid anhydride (e) and 25.09 gof diethylene glycol monoethyl ether acetate as a solvent were added andthe mixture was reacted for 4 hours at 95° C. to give the resin solutioncontaining 60% by weight of urethane resin (A) soluble in aqueous alkalisolution. This resin solution is referred as A-5. The acid valuemeasured was 60 mgKOH/g (the solid-component acid value: 100 mgKOH/g).

Synthetic Example 6

368.0 g of RE 310S (manufactured by Nippon Kayaku Co., Ltd.,bifunctional bisphenol A type epoxy resin, the epoxy equivalent 184g/equivalent), bisphenol A type epoxy resin; 172.2 g of methacrylic acid(Molecular weight 86.09); 4.37 g of 2,6-di-tert-butyl-p-cresol, thermalpolymerization inhibitor; and 1.62 g of triphenyl phosphine, reactioncatalyst; were mixed in 3 L flask attached with stirring device andreflux condenser, and were reacted at 98° C. until the acid value of thereaction solution became not more than 0.5 mgKOH/g to give diol compound(b) having the ethylenically unsaturated group in its molecule(Theoretical molecular weight: 540.18).

Then, 757.4 g of carbitol acetate, reaction solvent; and 319.4 g ofdimethylol propionic acid (Molecular weight 134.16), diol compound (c)having the carboxy group in its molecule; were added to this reactionsolution and temperature was raised to 45° C. 546.9 g oftrimethylhexamethylene diisocyanate (Molecular weight 210.27) wasgradually dropped to this solution as the reaction temperature wasmaintained under 65° C. After dropping, the temperature was raised to80° C. and the reaction was continued for 6 hours until the absorbanceat approximately 2250 cm⁻¹ of IR spectrum disappeared.

And then, 15.3 g of succinic anhydride (Molecular weight 100.07), cyclicacid anhydride; and 8.25 g of carbitol acetate, reaction solvent; wereadded and reacted for 3 hours at 98° C. to give the resin solutioncontaining 65% by weight of urethane resin (A) soluble in aqueous alkalisolution. (This solution is referred as A-6.) The acid value measuredwas 63.0 mgKOH/g (the solid-component acid value: 96.9 mgKOH/g).

Synthetic Example 7

368.0 g of RE 310S (manufactured by Nippon Kayaku Co., Ltd.,bifunctional bisphenol A type epoxy resin, the epoxy equivalent 184g/equivalent), a bisphenol A type epoxy resin; 172.2 g of methacrylicacid (Molecular weight 86.09); 4.37 g of 2,6-di-tert-butyl-p-cresol,thermal polymerization inhibitor; and 1.62 g of triphenyl phosphine,reaction catalyst; were mixed in a 3 L flask attached with stirringdevice and reflux condenser, and were reacted at 98° C. until the acidvalue of the reaction solution became not more than 0.5 mgKOH/g to givediol compound (b) having the ethylenically unsaturated group in itsmolecule. (Theoretical molecular weight: 540.18)

Then, 654.2 g of carbitol acetate, reaction solvent; and 261.4 g ofdimethylol propionic acid (Molecular weight 134.16), diol compound (c)having the carboxy group in its molecule; were added to this reactionsolution and temperature was raised to 45° C. 413.4 g oftrimethylhexamethylene diisocyanate (Molecular weight 210.27) wasgradually dropped to this solution as the reaction temperature wasmaintained under 65° C. After dropping, the temperature was raised to80° C. and the reaction was continued for 6 hours until the absorbanceat approximately 2250 cm⁻¹ of IR spectrum disappeared.

And then, 26.4 g of succinic anhydride (Molecular weight 100.07), cyclicacid anhydride; and 14.2 g of carbitol acetate, reaction solvent; wereadded and reacted for 3 hours at 98° C. to give the resin solutioncontaining 65% by weight of urethane resin (A) soluble in aqueous alkalisolution. (This solution is referred as A-7.) The acid value measuredwas 64.3 mgKOH/g (the solid-component acid value: 98.9 mgKOH/g).

Example 1

A photosensitive resin composition was accomplished by mixing with A-1obtained in synthetic example 1 in the ratio shown in Table 1 andkneading with 3-roll mill. This was coated on a print board by screenprinting method to give 15 to 25 μm of dried film thickness and then thefilm was dried for 30 minutes with hot air at 80° C. Then, ultravioletlight was irradiated through a mask on which circuit pattern was drawnusing ultraviolet light exposure device (Oak Manufacturing Co., Ltd.,Model HMW-680GW). And then, spraying development was carried out with 1%of aqueous sodium carbonate solution and the resin of ultraviolet lightnot-irradiated part was removed (development). After washing with waterand drying, the print board was heated and cured by hot air dryer with150° C. to give a cured film. As described in test examples later, thecured product was tested on photosensitivity, surface glazing, baseboard warping, bending property, adhesion property, pencil hardness,solvent resistance, acid resistance, heat resistance, and gold platingresistance. The results are shown in Table 2.

Example 2

A photosensitive resin composition was accomplished by mixing with A-2obtained in synthetic example 2 in the ratio shown in Table 1 andkneading with 3-roll mill. This was coated on a print board by screenprinting method to givel5 to 25 μm of dried film thickness and then thefilm was dried for 30 minutes with hot air at 80° C. Then, ultravioletlight was irradiated through a mask on which circuit pattern was drawnusing ultraviolet light exposure device (Oak Manufacturing Co., Ltd.,Model HMW-680GW). And then, spraying development was carried out with 1%of aqueous sodium carbonate solution and the resin of ultraviolet lightnot-irradiated part was removed (development). After washing with waterand drying, the print board was heated and cured by hot air dryer with150° C. to give a cured film. As shown in test examples later, eachproperty test was carried out. The results are shown in Table 2.

Example 3

54.44 g of resin solution A-3 obtained in synthetic example 3; 3.54 g ofHX-220 (manufactured by Nippon Kayaku Co., Ltd., bifunctional acrylateresin), reactive crosslinking agent (C); 4.72 g of Irgacure 907(manufactured by Vantico Co., Ltd., photo polymerization initiator) and0.47 g of Kayacure DETX-S (manufactured by Nippon Kayaku Co., Ltd.,photopolymerization initiator), photopolymerization initiator (B); 14.83g of YX-8000 (manufactured by Japan Epoxy Resin Co., Ltd., bifunctionalhydrogenated bisphenol A type epoxy resin, the epoxy equivalent 202.06g/equivalent), curing component (D); 1.05 g of melainine, heat curingcatalyst; and 20.95 g of methyl ethyl ketone, concentration adjustingsolvent; were mixed with bead mill to suspend homogeneously giving thephotosensitive resin composition.

The composition obtained was coated homogeneously on the polyethyleneterephthalate film, which was a supporting film, by the roll coatmethod, and was passed through hot air drying oven at 70° C. to form theresin layer having 30 μm thickness, and then polyethylene film as aprotective film was attached on the resin layer to give a dry film. Theresin layer of the dry film obtained was attached on whole polyimideprint base board (cupper circuit thickness: 12 μm, polyimide filmthickness: 25 μm) by heating roll at 80° C. while peeling off theprotective film.

Then, ultraviolet light was irradiated by using ultraviolet lightreduced projection exposure device in which negative mask having lightguide pattern was installed (volume irradiated: 500 mJ/cm²).

After irradiation, the supporting film was peeled off from the resin andwas developed with 0.25% aqueous tetramethylammonium solution for 30seconds to dissolve and remove undeveloped parts. After washing withwater and drying, the print base board was heated and cured for 30minutes by hot air drying device at 150° C. to give a curing film.Clearness of the curing product obtained was good and 50 μm pattern wasresolved.

Examples 4 and 5

A photosensitive resin composition of the present invention wasaccomplished by mixing with A-6 or A-7 obtained in synthetic example 6or 7 in the ratio shown in Table 1, and kneading with 3-roll mill. Thiswas coated on a print board by screen printing method to give 15 to 25μm of dried film thickness and then the film was dried for 30 minuteswith hot air at 80° C. Then, ultraviolet light was irradiated through amask on which circuit pattern was drawn using ultraviolet light exposuredevice (Oak Manufacturing Co., Ltd., Model HMW-680GW). And then,spraying development was carried out with 1% of aqueous sodium carbonatesolution and the resin of ultraviolet light not-irradiated part wasremoved (development). After washing with water and drying, the printboard was heated and cured by hot air dryer with 150° C. to give a curedfilm. As described in test examples later, the cured product was testedon photosensitivity, surface glazing, base board warping, bendingproperty, adhesion property, pencil hardness, solvent resistance, acidresistance, heat resistance, and gold plating resistance. The resultsare shown in Table 2. TABLE 1 Composition of photosensitive resincomposition Remark Example 1 Example 2 Example 4 Example 5 Resinsolution A-1 51.80 A-2 51.80 A-6 51.80 A-7 51.80 Reactive crosslinkingDPCA-60 1 3.38 3.38 agent (C) HX-220 2 3.38 3.38 PhotopolymerizationIrgacure 907 3 4.50 4.50 4.50 4.50 initiator (B) DETX-S 4 0.45 0.45 0.450.45 Curing component (D) YX-4000 5 17.62 17.62 NC-3000 6 17.62 17.62Heat curing catalyst Melamine 1.00 1.00 1.00 1.00 Filler and othersBarium sulfate 15.15 15.15 15.15 15.15 Phthalocyanine 0.45 0.45 0.450.45 blue Additive BYK-354 7 0.39 0.39 0.39 0.39 KS-66 8 0.39 0.39 0.390.39 Solvent CA 9 4.87 4.87 4.87 4.87 Remark: 1 Nippon Kayaku Co., Ltd.dipentaerythritol hexaacrylate modified by ε-caprolactone 2 NipponKayaku Co., Ltd. hydroxypivalic acid neopentylglycol diacrylate modifiedby ε-caprolactone 3 Vantico Co., Ltd.2-methyl-1-(4-(methylthio)phenyl)-2- morphorinopropan-1-one 4 NipponKayaku Co., Ltd. Kayacure DETX-S, 2,4-diethylthioxantone 5 Japan EpoxyResin Co., Ltd. Bifunctional bixylenol type epoxy resin 6 Nippon KayakuCo., Ltd. Bifunctional biphenol type epoxy resin 7 Bic Chemi Co., Ltd.Leveling agent 8 Shin'etsu Chemicals Co., Ltd. Anti-foaming agent 9Osaka Organics Co., Ltd. Carbitol acetate (solvent)

Comparison Example

To produce the photopolymerization resin composition disclosed inexamples of reference patent 5 (JP Laid Open Patent H9-52925), we triedto synthesize the resin disclosed in synthetic example 1 of the samepatent.

48.45 g of YD-128 (manufactured by Toto Kasei Co., Ltd., the epoxyequivalent 186.3), bisphenol A type epoxy resin; 18.66 g of acrylicacid; 0.007 g of hydroquinone; 41.97 g of carbitol acetate; and 28.03 gof solvent naphtha; were mixed and dissolved for 30 minutes at 100° C.Then dimethylbenzylamine 0.0704 g was added and temperature was raisedto 110° C. while bubbling air, and stirring was continued. After 5hours, gel formation occurred and the target resin was not obtained.

Test Examples

Test method for each property is shown in the following.

(Tracking property) Rub absorbent cotton on the film, after coating onthe base board and drying, to measure tacking property of the film.

O - - - Absorbent cotton was not tacked on the film.

X - - - Cotton waste was tacked on the film.

(Developing property) Use the following benchmarks for evaluation.

O - - - On development; ink was completely removed and development wascarried out.

X - - - On development; some part was not developed.

(Image resolution property) Irradiate and expose the coating film afterdrying, to which 50 μm negative pattern was adhered, with 200 mJ/cm² oftotal ultraviolet light volume. Then develop it for 60 seconds with 1%aqueous sodium carbonate solution and 2.0 kg/cm² of spraying pressure,and observe microscopically transferred pattern. Use the followingbenchmarks for evaluation.

O - - - Pattern edge is linear. Resolution was achieved.

X - - - Peel-off occurs or pattern edge is irregular.

(Photosensitivity) Adhere 21 steps Step Tablet (Kodak) to the coatingfilm after dried, irradiate total light volume 500 mJ/cm² of ultravioletlight and expose to ultraviolet light. Then develop it for 60 secondswith 1% aqueous sodium carbonate solution and 2.0 kg/cm² of sprayingpressure, and count steps of coating film remained without beingdeveloped.

(Surface glazing) Irradiate total light volume 500 mJ/cm² of ultravioletlight to the coating film after dried and expose to ultraviolet light.Then develop it for 60 seconds with 1% aqueous sodium carbonate solutionand 2.0 kg/cm² of spraying pressure, and observe the cured film. Use thefollowing benchmarks for evaluation.

O - - - Absolutely not cloudy

X - - - More or less cloudy

(Base board warping) Use the following benchmarks for evaluation.

O - - - No warp on the base board

Δ - - - Base board warp very slightly is observed.

X - - - Base board warp is observed.

(Bending property) Bend the curing film 180 degree and observe. Use thefollowing benchmarks for evaluation.

O - - - No crack up on the film surface

X - - - Film is cracked up.

(Adhesion property) As directed to JIS K5400, gridiron the test piecewith 1 mm width to make 100 grids and use Scotch tape (R) to carry outpeeling-off test. Observe peel-off of grid and use the followingbenchmarks for evaluation.

O - - - No peeling-off

X - - - Peeling-off is observed.

(Pencil hardness) Evaluate as directed to JIS K5400.

(Solvent resistance) Immerse the test piece in isopropyl alcohol for 30minutes at room temperature. Ensure no abnormality on exteriorappearance and then carry out peeling test using Scotch tape (R). Usethe following benchmarks for evaluation.

O - - - No abnormality, no swelling and no peeling-off on exteriorappearance of the coating film

X - - - Swelling and peeling-off of the coating film are observed.

(Acid resistance) Immerse the piece for 30 minutes in 10% aqueoushydrogen chloride solution. Ensure no abnormality on exterior appearanceand then carry out peeling test using Scotch tape (R). Use the followingbenchmarks for evaluation.

O - - - No abnormality, no swelling and no peeling-off on exteriorappearance of the coating film

X - - - Swelling and peeling-off of the coating film are observed.

(Heat resistance) Coat rosin-type plux on the test piece and immerse for5 seconds in fused solder bath at 260° C. Repeat the same process threetimes. After cooling down to room temperature and carry out peeling-offtest using Scotch tape (R). Use the following benchmarks for evaluation.

O - - - No abnormality, no swelling and no peeling-off on exteriorappearance of the coating film

X - - - Swelling and peeling-off on the coating film are observed.

(Gold plating resistance) Immerse a test piece of the base board inacidic defating solution (Nihon MacDiarmid Co. Ltd., 20% by volumeaqueous solution of Metex L-5B) for 3 minutes at 30° C.; then wash withwater; immerse in 14.4% by weight aqueous ammonium persulfate solutionat room temperature for 3 minutes; wash with water; immerse the testpiece in 10% by volume aqueous hydrogen sulfate solution for 1 minute;and wash with water. Immerse this base board in a catalyst solution(made by Meltex Co., Ltd., 10% by volume aqueous solution of metal plateactivator 350) for 7 minutes at 30° C., wash with water, immerse innickel plating solution (manufactured by Meltex Co., Ltd., 20% by volumeaqueous solution of Melplate Ni-865M, pH 4.6) for 20 minutes at 85° C.to carry out nickel plating, and then immerse in 10% by volume aqueoushydrogen sulfate solution for 1 minute at room temperature and wash withwater. Then, immerse the test piece in gold plating solution(manufactured by Meltex Co., Ltd., 15% by volume Aurolectroless UP and3% by volume aqueous potassium gold cyanide, pH 6) for 10 minutes at 95°C. to carry out electroless gold plating, wash with water, immerse inwann water at 60° C. for 3 minutes, wash with water, and dry it. AdhereScotch tape to the electroless gold plating evaluation base board andpeel off the tape. Observe the condition.

O - - - No abnormality

X - - - More or less there is peeling-off.

(PCT property resistance) Stand a test base board in water for 96 hoursunder 2 atmospheric pressures at 121° C.; ensure no abnormality onexterior appearance, and carry out peeling-off test using Scotch tape(R) and use the following benchmarks for evaluation.

O - - - No abnormality, no swelling and no peeling-off on exteriorappearance of the coating film

X - - - Swelling and peeling-off of the coating film are observed.

(Heat and shock resistance) Repeatedly treat a test piece for 30 minutesat −55° C. and for 30 minutes at 125° C. and after 1000 times repeated,observe microscopically the test piece and use the following benchmarksfor evaluation.

O - - - No crack observed on the coating film

X - - - There is a crack observed on the coating film. TABLE 2 TestResults Test Term Example 1 Example 2 Example 4 Example 5 Tackingproperty ◯ ◯ ◯ ◯ Developing ◯ ◯ ◯ ◯ property Image resolution ◯ ◯ ◯ ◯property Photosensitivity 10 10 10 11 Surface glazing ◯ ◯ ◯ ◯ Base board◯ ◯ ◯ ◯ warping Bending property ◯ ◯ ◯ ◯ Adhesion property ◯ ◯ ◯ ◯Pencil hardness 5H 4H 4H 5H Solvent resistance ◯ ◯ ◯ ◯ Acid resistance ◯◯ ◯ ◯ Heat resistance ◯ ◯ Δ ◯ Gold plating ◯ ◯ ◯ ◯ resistance PCTproperty ◯ ◯ ◯ ◯ resistance Heat and shock ◯ ◯ ◯ ◯ resistance

The above results obviously showed that the polyurethane compoundsoluble in aqueous alkali solution and the photosensitive resincomposition using it of the present invention had no tacking property;was highly photosensitive; the curing film thereof was hot solderresistant, chemical resistant, gold plating resistant, had excellentproperties such as high insulation property; no crack on the surface ofthe curing material occurred; if the base board like thin film was used,that was the photosensitive resin composition for the print base boardwithout warp on the base board.

The polyurethane compound soluble in aqueous alkali solution producedwithout any catalyst and to which an acid was added, and thephotosensitive resin composition thereof has an excellentphotosensitivity in the formation of photoexposure cured coating film byactinic energy rays, has an excellent photosensitivity to actinic energyrays to obtain a fine image corresponding to a high function printwiring board, can form a pattern by developing with a diluted aqueousalkali solution, and the cured film obtained by post curing processingwith heat according to need has satisfactory flexibility, bendingproperty, adhesion property, pencil hardness, chemical resistance, acidresistance, heat resistance, gold plating resistance, electroless goldplating resistance, tin plating resistance and high insulation property.Especially it is appropriate to produce a solder mask for flexible printwiring board, an insulation film between layers for multi layer printwiring board and a light guide.

1. A photosensitive resin composition comprising: urethane resin solublein aqueous alkali solution obtained by urethanization reaction, withoutany catalyst, of a diisocyanate compound, a first diol compound havingan ethylenically unsaturated group, a second diol compound having acarboxyl group, and a third diol compound not having any ethylenicallyunsaturated group or carboxyl group as an optional component; and by areaction with a cyclic acid anhydride; a photo polymerizationinitiatory; and a reactive cross-linking agent.
 2. The photosensitiveresin composition according to claim 1 comprising: a curing component asan optional component.
 3. The photosensitive resin composition accordingto claim 1 wherein the solid-component acid value of said urethane resinis in the range of 30 to 150 mgKOH/g.
 4. The photosensitive resincomposition according to claim 1, wherein said first diol compoundhaving the ethylenically unsaturated group is a reaction product of anepoxy compound having two epoxy groups and (meth)acrylic acid orcinnamic acid; and said cyclic acid anhydride is dibasic acidmonoanhydride and/or tribasic acid monoanhydride.
 5. The photosensitiveresin composition according to claim 1, wherein said diisocyanatecompound is isophorone diisocyanate and/or trimethylhexamethylenediisocyanate; said first diol compound having the ethylenicallyunsaturated group is the reaction product of bisphenol A type epoxyresin and methacrylic acid; said second diol compound having thecarboxyl group is dimethylol propionic acid; and said cyclic acidanhydride is succinic anhydride.
 6. The photosensitive resin compositionaccording to claim 1 wherein said urethane resin soluble in aqueousalkali solution is obtained by adding trimethylhexamethylenediisocyanate to a mixture of dimethylol propionic acid and a reactionproduct of bisphenol A type epoxy resin and methacrylic acid, and thenreacting with succinic anhydride.
 7. The photosensitive resincomposition according to claim 5 wherein the epoxy equivalent of saidbisphenol A type epoxy resin is in the range of 100 to 900 g/equivalent.8. The photosensitive resin composition according to claim 6, wherein anequivalent ratio, in the reaction to obtain the urethane resin (A)soluble in aqueous alkali solution, of a hydroxyl group in a mixture ofdimethylol propionic acid and the reacted product of bisphenol A typeepoxy resin and methacrylic acid, to isocyanate group oftrimethylhexamethylene diisocyanate is in the range of 1.1 to 2.0.
 9. Amanufacturing method of a curing product comprising: irradiating actinicenergy rays on the photosensitive resin composition according toclaim
 1. 10. A base material having a layer of the curing productproduced by the manufacturing method according to claim
 9. 11. A producthaving the base material according to claim
 10. 12. A manufacturingmethod of a solder mask for a flexible print wiring board, of ainsulation film between layers for a multilayer print wiring board, orof a photosensitive light guide, comprising the steps of; a coatingprocess of a photosensitive resin composition according to claim 1, anirradiating process of actinic energy rays for curing, and a treatingprocess with alkali and/or heat.
 13. A photosensitive resin compositioncomprising: urethane resin being soluble in aqueous alkali solution,said urethane resin obtained by reacting a diisocyanate compound, afirst diol compound having an ethylenically unsaturated group, a seconddiol compound having a carboxyl group, a third diol compound not havingan ethylenically unsaturated group or a carboxyl group as an optionalcomponent without any catalyst; and by reacting with a cyclic acidanhydride; a photo polymerization initiator; and a reactivecross-linking agent.
 14. A photosensitive resin composition according toclaim 13, wherein the diisocyanate compound comprises: phenylenediisocyanate, tolylene diisocyanate, xylylene diisocyanate,tetramethylxylylene diisocyanate, diphenylmethane diisocyanate,naphthalene diisocyanate, toludene diisocyanate, hexamethylenediisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate,allylenesulfonether diisocyanate, allylcyan diisocyanate, N-acyldiisocyanate, trimethylhexamethylene diisocyanate,1,3-bis-(isocyanatomethyl)cyclohexane and norbornan diisocyanate.
 15. Aphotosensitive resin composition according to claim 13, wherein thefirst diol compound is a reaction product of an epoxy compound havingtwo epoxy groups and (meth)acrylic acid or cinnamic acid, or a reactionproduct of bisphenol A type epoxy resin or hydrogenated bisphenol A typeepoxy resin and (meth)acrylic acid.
 16. A photosensitive resincomposition according to claim 13, wherein the first diol compoundcomprises a reaction product of dimethylol propionic acid and2-hydroxyethyl (meth)acrylate, a reaction product of dimethylolpropionic acid and 2-hydroxypropyl (meth)acrylate, a reaction product ofdimethylol butanoic acid and 2-hydroxyethyl (meth)acrylate, a reactionproduct of dimethylol butanoic acid and 2-hydroxypropyl (meth)acrylate,a reaction product of an epoxy compound having two epoxy groups and(meth)acrylic acid or cinnamic acid, or a reaction product of a phenoliccompound having two phenolic hydroxyl groups and glycidyl(meth)acrylate.
 17. A photosensitive resin composition according toclaim 15, wherein the epoxy compound comprises: a phenyl diglycidylether, a bisphenol type epoxy compound, a hydrogenated bisphenol typeepoxy compound, a halogenated bisphenol type epoxy compound, an acyclicdiglycidyl ether compound, an aliphatic diglycidyl ether, a polysulfidetype diglycidyl ether compound, or a biphenol type epoxy resin.
 18. Aphotosensitive resin composition according to claim 13, wherein thesecond diol compound is a compound with two alcoholic hydroxy groups andmore than one carboxylic group.
 19. A photosensitive resin compositionaccording to claim 13, wherein the second diol compound comprises:dimethylol propionic acid or dimethylol butanoic acid(2,2-bis(hydroxymethylbutanoic acid).
 20. A photosensitive resincomposition according to claim 13, wherein the third diol compound is analiphatic diol compound or alicyclic diol compound which has noethylenically unsaturated group or no carboxyl group, and in which twoalcoholic hydroxy groups are not attached to the same carbon.
 21. Aphotosensitive resin composition according to claim 13, wherein thethird diol compound comprises: (poly)ethylene glycol, (poly)propyleneglycol, trimethylene glycol, 1,4-butanediol, 1.5-pentanediol,1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol,1,10-decanediol, hydrobenzoin, benzpinacol, cyclopentane-1,2-diol,cyclohexane-1,2-diol, cyclohexane-1,4-diol, cyclohexane-1,2-dimethanol,cyclohexane-1,4-dimethanol, a butadiene-acrylonitrile copolymer having ahydroxy group at its end, a spiro glycol having a hydroxyl group at itsend, a dioxane glycol having a hydroxy group at its end, atricyclodecane dimethanol having a hydroxyl group at its end, amacromonomer having a hydroxyl group at its end and a polystyrene sidechain, hydrogenated bisphenol A, hydrogenated bisphenol F, or a reactionproduct of one of the diol compounds above and an oxide.
 22. Aphotosensitive resin composition according to claim 13, wherein thecyclic acid anhydride is a dibasic acid monoanhydride in which thedibasic acid forms an intramolecular acid anhydride, a tribasic acidmonoanhydride in which two carboxylic groups of the tribasic acid forman intramolecular anhydride, or a mixture of the above acidmonoanhydride.
 23. A photosensitive resin composition according to claim13, wherein the cyclic acid anhydride comprises: maleic anhydride,succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydro phthalic anhydride, methyl endmethylenetetrahydro phthalic anhydride, methyltetrahydro phthalic anhydride,trimellitic anhydride, tetrahydro trimellitic anhydride or hexahydrotrimellitic anhydride.
 24. A photosensitive resin composition accordingto claim 13, wherein the photo polymerization initiator comprises: abenzoin compound, an acetophenone compound, an anthraquinone compound, athioxanthone compound, a ketal compound, a benzophenone compound, or aphosphine oxide compound.
 25. A photosensitive resin compositionaccording to claim 13, wherein the reactive cross-linking agent is a(meth)acrylate derivative.
 26. A photosensitive resin compositionaccording to claim 13, wherein the reactive cross-linking agentcomprises: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, 1,4-butanediol-mono(meth)acrylate, carbitol(meth)acrylate, acryloyl morpholine, a semiester which is a reactionproduct of (meth)acrylate having hydroxy group and polycarboxylic acidanhydride, polyethylene glycol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, trimethylol propane polyethoxytri(meth)acrylate,glycerine polypropoxytri(meth)acrylate, di(meth)acrylate which is areaction product of hydroxylpivalic acid neopentylglycol andε-caprolactone, pentaerythrytol tetra(meth)acrylate, poly(meth)acrylatewhich is a reaction product of dipentaerythrytol and ε-caprolatone, orepoxy (meth)acrylate which is a reaction product of mono or polyglycidyl acrylate and (meth)acrylic acid.